Transmission-drive for speedometers.



4 F. A. ROSS. TRANSMISSION DRIVE FOR SPEEDOMHEHS.

APPLICATION FILID HAY I. 1914; Patentad UNITED STATES," PATENT OFFICE.

FRANK ROSS, OF EVANSTON, ILLINOIS, ASSIGNQB 'IO STEWART-MARINE? SPEED- OME'IER CORPORATION, OF CHICA O. ILLINOIS, A CORPORATION OF VIRGINIA.

4 I i TRANSMISSION-DRIVE FOR SPEEDOMETERS.

Application filed May 1, 1914, Serial No. 885,599.

\ To all 'wh'om it may concern Be it known that I, FRANK A Ross, a citizen of the United States, residing at Evanston, in the county of Cook and State of Illinois, have invented new and useful Improvements in 'lransmission-Drives for Speedometers, of which the following isa specification, reference being bad to the accompanying drawings. forming a part thereof.

The purpose of this invention is to provide improved means for connecting a speedometer to the. road wheels of an automobile by way of the automobile transmis; sion.

It consists of the features and elements shown and described as set out in the claim.

In the drawings :-Figure 1 is a diagrammatic view indicating in transverse eleva tion the relative positions of the speedometer and the transmission to which it is con nected. Fig. 2 is an elevation of the transmission shown in Fig. 1 with parts broken away to reveal the speedometer drive gearing. Fig. 3 is a detail section taken as indicated at line 3-3 on Fig. 2.

in Fig. 1, A, indicates conventionally the dash-board of an automobile, the side rame members being shown in section at B, 13.

1, represents a speedometer mounted on the dash-board and provided with a flexible or jointed drive shaft, I), which extends into the housing, E, of the automobile transmission. The transmission which is more fully represented in Figs. 2 and E5 is of the usual type comprising a main shaft, l". and a side shaft, (i, the shaft, F, being at all' times positively connected with the driving wheels of the vehicle so that its speed of rotation bears a constant ratio to the speed of such wheels. Variations in speed ratio between the engine and the road wheels is obtained when desired by transmitting the power from the engine to gears on the side shaft, (i, and through other gears on said shaft to a gear on the shaft, 1*, as for example, the gear, F while the so-called direct drive is obtained by clutching the engine shaft directly to the. shaft, 1 by means not shown in the drawings. Such mechanisms are old in the art and are well understood.

The present invention consists in providing the shaft, 1', with a special an, J, shown as a spiral gear, and in fitting into the transmission housing. E, a small shaft, K, carrying a second spiral gear, L, positioned and formed to mesh with the gear, J. The gear, J, being keyed at J to the shaft, F, will at all times transmit the rotation of said shaft to the shaft, K, and thence to the spemldmeter, through the jointed shaft, D. which is directly coupled to the shaft, K, as shown at D, in Fig. 2,

Further features of the invention consist in the fittings which are provided for mounting the shaft. K, in the housing, E. Preferably, the housing is cast with an annular boss, E. into which is forced the outer ball race, M, of an annular ball hearing, while the reduced end, K, of the shaft, K, is then driven into the inner member, MP, of the ball race. The gear, L, being either formed integrally with the shaft, K, or secured rigidly to it is thus positioned with respect to tie gear, J. At the opposite end of the shaft, K. the housing is aliertured and a cap in the form of a flanged sleeve. N, is fitted into the aperture with its flange, N, abutting the outer wall of the casing, l]. \Vithin the inner end of the sleeve, N. the outer race, I". of an annrdar ball bearing is secured by driving fit whil its inner race, P, is driven on to the end of the shaft. K. 'lhis cnd of the shaft extends at 1', toward the other end of the sleeve, N, where it is coupled with the standard coupling, D, of the connecting shaft, 1). It will he noted that since the gear, L, must be rigid with the shaft. K, when the latter is inserted into the housing, E, the opening which is closed by the flanged sleeve, N, will be made large enough to admit the gear, L, as well as the shaft, K.

With the parts assembled as above described, connection between the speedometer, (1, amt-the road whebls of the vehicle is effected in the simplest possible manner, since the transmission housing, E, is generally located almost directly below the dash-board or just slightly rearward of it.

I claim In an automobile, in combination with a transmission comprising a housing and a shaft inclosed thereby having a fixed s weed ratio with respect to the road wheels 0 the vehicle, a. gear on said shaft within the housing,-a small shaft and a gear fixed thereon in position to mesh with the first- A i P l Specification of Letters Patent. Patented Nov. 14, 1916.

mentioned gear, a journal bearing for one, shaft dimensioned at the end to fit said end of Blid small shaft carried by one wall sleeve for connection therewith.

of the housing, the opgosibe wall having In testim'on whereof I have hereunto set an aperture large enoug to udmi the ear mfy hand, at hieago, Iilinois, this 25th day 6 onhe smell ehefa, a fitting fume 3o fiegee 0 April, 1914.

881 aperture an can mg a. secdn ring for said shafhjni fittingtermineting FRANK Ross in a sleeve, 0 jointed shaft ogerat'ivel con- Witnesses:

necicd with said smell sha t oqtsicih the V. M. Lmrn, 10, easing, and e tubuhucasing for sand jointed R. H. WALPOIE. 

